The field of the invention relates to material or article handling involving an apparatus which includes a load carrier swingable in the vertical plane. More in particular, the invention relates to such an apparatus wherein the carrier is a scoop.
Towable earth digging apparatuses are known. One such example is U.S. Pat. No. 4,925,358, (xe2x80x9cthe patentxe2x80x9d) to the inventors, Paul Cook and Karl Schulz, the entire disclosure of which is incorporated herein by reference. This device is a backhoe type of apparatus which is adapted for direct over-the-road trailering by an automobile-type vehicle. At one end of the device is an articulated swing with a scoop for excavating earth. The swing is attached to the frame of the apparatus on the back side, which is why the device is typically known as a backhoe. On the front of the device is a hitch for attaching it to a towing vehicle such as a truck or an automobile. When the device is not attached to a truck or car for movement, the device is deployed on an excavation site, which can be either a street or some non-friction surface. The device is moved around on four wheels until it is situated at a place where it can then be used to excavate. Then the apparatus is set up in a digging position. The device of the ""358 patent is set up in the digging position by two outriggers on the back side, and one outrigger on the front, so the machine is set up on a tripod. The wheels that are used to maneuver the vehicle from one site to the next can be raised or be in contact with the ground, but in effect, the machine""s weight is set up on the outriggers fore and aft to establish a stable three point digging platform. The problem with this device of the ""358 patent is lack of versatility at the excavation site.
There is a need for such towable earth digging apparatuses to be able to plow and backfill holes, much like a bulldozer can move earth. The typical tractor loader backhoe, which is moved from one excavation site to another excavation site on a separate trailer, are large tractors having a loader bucket on the front of the device and a hoe or swing on the rear of the device. This is an excellent earth moving apparatus as both the ability to backfill or plow and the ability to excavate with the swing or boom, are provided in a single device. A towable, earth digging apparatus, such as is contemplated by the ""358 patent, cannot easily accommodate the plow or backfill blade because on the front end the device must be towed with a hitch.
Furthermore, because of the compact nature of the towable earth digging apparatus such as is shown in the ""358 patent, the addition of a backfill blade to the well-balanced three point structure must be done in such a way as to provide stability to the device for the swing or boom while being towed, as well as to the device when it is in a digging position.
Therefore, there is an unfilled need for a small maneuverable multi-functional apparatus that can be towed at highway speed behind a towing vehicle such as a light truck. The apparatus should be capable of excavating, back-filling, and other construction site tasks.
The invention is a self-contained towable backhoe apparatus adapted for direct over-the-road towing by a truck and an automobile-type vehicle, and includes several features. One feature is a support frame having first and second ends and having a trailer hitch attached to the first end. Another feature is the wheels supporting the frame at the first end and the second end. Another feature includes a backfill blade movably attached to the second end of the frame. The apparatus also includes an articulated arm assembly, pivotably mounted on the second end of the frame. The articulated arm assembly can have many configurations, including a backhoe.
It is preferred that the apparatus have a stabilizer, sometimes known as an outrigger, secured to the first end of the frame for stabilizing the apparatus while in a digging position. This stabilizer can have a street pad for engaging the surface of the street, and to protect the street so it does not penetrate the tarmac. The stabilizer can also have a spade or a digging plate, for example, for penetrating a surface while the apparatus is in a digging position for surfaces such as earth and gravel, where the surface does not need such protection. This first end stabilizer can be both a combination of a street pad and a digging plate or spade. The movable backfill blade is capable of movement to a raised position for supporting the articulated arm during transport, and movement to at least one lowered ground engaging position capable of stabilizing the apparatus for digging, for earth moving, or any combination thereof.
There is at least one drive wheel for the device if a power drive is a required feature for a particular construction site or job. The articulated arm can also include standard types of tool attachments, for example, a scoop, digging bucket, auger, fork, scraper, breaker, cutting tool, or a grapple. The articulated arm can also include a brush for cleaning streets or walls.
The backfill blade is capable of being tilted from one side to the other to accommodate irregularities of surfaces, as well as manipulate the apparatus. The backfill blade is also capable of being raised and lowered.
Such an apparatus made in accordance with the description herein, is capable of being towed by a light truck and car, over the road at highway speeds because of its relatively light weight. The apparatus is adapted for direct trailering on its own wheels behind a towing vehicle, without need for an independent trailer, that is, equipment carrier, to carry the apparatus. Alternatively, the point of balance may be altered by extension of the boom and swing arm to unweight the tow hitch and enable an individual to lift the tow hitch off of the towing ball. Once at a particular site an individual can lift the hitch off of the towing ball of the towing vehicle by use of the first end stabilizer hydraulic cylinder to lift the first end of the apparatus. Once disconnected from the towing vehicle, the apparatus can be moved about from digging location to digging location on its four wheels. The device is capable of being driven, preferably by a hydraulic drive connected to least one wheel. Suitable engines, hydraulic drives and pumps are located on the device in such a manner as to move the device from digging site to digging site, and to excavate.
The location of motors, pumps, hydraulic reservoirs and the like, are important from the point of view of establishing a well balanced apparatus. The balance can be affected by the extension or retraction of the articulated arm. By extension of the articulated arm from the second end of the apparatus, the apparatus can be made to xe2x80x9ccrab-walkxe2x80x9d and straddle or cross ditches.
The digging position is established by deploying the first end stabilizer and the second end backfill blade into contact with the surface. If on a street that needs protection, it is preferred that the surfaces of the supporting structure are protected with pads so as to prevent damage to the tarmac. If the surface is a non-friction surface such as gravel or dirt, the first end stabilizer and the second end backfill blade can actually penetrate the surface and provide anchoring forces against the digging forces of the articulated arm.
Therefore, it is an object of the invention to provide an apparatus which on the first end has a hitch to be towed by a truck and an automobile-type vehicle, and on the second end as both an excavating backhoe, which can also have other devices useful in and around a construction site attached to the end of the arm, as well as a backfill.
It is yet another object of the device to provide a two-point support for a towable backhoe wherein the digging platform is provided on the first end, with a centrally located stabilizer, and wherein the second end of the frame is supported in the digging position by a backfill blade, without the use of outriggers.